This invention pertains to medical electrodes, and more particularly, is concerned with electrodes for use in ion therapy. Many types of wounds or lesions may be treated through use of a porous metalized treatment electrode energized by a constant current generator. This treatment electrode is typically in the form of a film of active metallic material (i.e. silver) which is plated or otherwise deposited over a porous synthetic fiber substrate.
Before use, the treatment electrode size is selected to approximate the shape of the patient's wound or lesion. The electrode is held by gauze or the like so as to be in contact with the patient's tissue (A return electrode is placed elsewhere on the patient). A tab extends from the electrode to provide electrical contact to the current generator. The patient completes an electric circuit formed by the current source, the treatment electrode as an anode, and the return electrode as a cathode. Current flow from the surface of the treatment electrode causes migration of metal ions from the metallic coating in the general direction of the return electrode.
Two problems arise during the treatment if the electrode is merely cut to the appropriate size by the manufacturer or by the user.
The first problem is due to loose or protruding fibers from a cut or sheared edge which can form a more intimate contact with the tissue than does the balance of the electrode. This contact provides a lower resistance path with corresponding preferential current and ion flow away from the central portion of the lesion.
The second problem occurs when a moderately conductive solution, such as normal saline, is used to soak the electrode and surrounding tissue for improving conduction and quantity of ion flow. A radial flow of current from the periphery of the infection site may occur. In both of these situations the diversion of current and ions away from the treatment site has the undesirable effect of reducing the desired ion concentration in the treatment area. Accordingly, it is the primary object of the invention to provide an electrode within a non-conductive, solution impervious border and a method for making the same.